To find out what we're doing wrong when we buy, order, and drink it, Business Insider spoke to Will Corby, head of coffee at Pact Coffee, a London startup that delivers freshly roasted and ground coffee by post.

Corby has been working in the coffee industry for 12 years, has won and judged global barista awards, ran his own coffee shops, and also has experience roasting.

"For the past 12 years, I've specialised in the absolute pinnacle of coffee quality and optimising the process of growing it, shipping it, importing it, brewing it," he said.

He's also been a head judge — appointed by the Colombian government — for the Colombian National Quality Competition for the past two years.

Now at Pact Coffee, he works on relationships with coffee founders to "develop practices, and increase quality and production in a sustainable manner," he said.

"We want to show the coffee in the best light we can, brew the coffee in the best possible way, [and] provide it to [people] in a way that makes it easy."

However, he said there's a lot of steps that go into making sure people have a good cup of coffee every day — and there are plenty of things you can do to make sure you're getting the most out of your java.

1. Not buying it fresh like you would vegetables or bread...

Pact Coffee

"If you walk into a supermarket in the UK, coffee is treated like a dried fruit," Cory said. "You find it in an aisle with cereal, dried peas, long-life things."

However, he explained, coffee isn't really a long-life product.

"One of the key things to explore is to drink your coffee really fresh," he said. "Think about it like fresh bread or vegetables."

One of the ways to do this is through a service like Pact, which sends out the coffee the day after it's been roasted, or from a local coffee shop or roaster.

2. ...Then keeping it for longer than a month

Coffee in the UK tends to be sold in 250g bags, according to Corby, which typically makes 13, 14, or 15 cups of coffee.

"That's about two-week supply if you drink it every day," he said, the ideal timeframe.

"You could be drinking it up to a month after it's been ground, but you'll notice a drop off in the quality," he said. "After a month, it will begin to taste stale."

He added that every time you open and close the bag, you're "allowing the aromatics to escape," meaning your coffee is losing its flavour.

3. Not making sure your grind size is consistent

You can usually buy whole beans or ground coffee suited for a cafetiere, drip, or a stove-top.

While this means you can successfully brew coffee in any of these methods, he said getting a consistent grind size is the real way to get a "really good brew" out of any method.

"Relatively small particles are going to over-extract, and make coffee taste more bitter than it should," he said.

Meanwhile, he added that large particles "add a [taste] that feels like acidity, which isn't very pleasant."

A "mish-mash" of both will provide "an astringent flavour," according to Corby.

"You need to buy coffee that is ground quite specifically for the brew method you're going to use to do it," he said. "Once you have particles your own size, brew the coffee."

4. Letting it brew for less than 4 minutes...

Most people in the UK use a cafetiere to brew their coffee — and it's important not to rush the process.

"If the grind size is perfect, ideally you want it to brew for four minutes, very slowly pushing it down through the cafetiere," Corby said.

5. ...And forgetting to decant what you don't drink straight away

While the idea of making your way through a cafetiere full of coffee might seem like a luxury, Corby said you should always take all liquid out after you've pushed it through, and decant whatever you're not drinking immediately into a different vessel.

"While the coffee's sat in the cafetiere, it will keep brewing and start to taste bitter," he said.

He said if you want coffee that has "delicious flavours," it's easier to taste them if you use a brew method that has a paper filter rather than metal, like a cafetiere.

He said metal "prevents you from detecting different tastes within the coffee."

6. Using a less-than-clean cafetiere

Often, people make a fresh pot of coffee without fully cleaning out their cafetiere from the last batch.

"You've got to keep it clean," Corby said. "You don't want to have any old coffee in there — it's just going to add bad flavour to the coffee."

He said the V60 drip coffee maker has become popular because "you can brew coffee relatively quickly, and it's faster to clean... you can just chuck the paper in the bin."

7. Adding milk and sugar when you don't need it

"As a company, we're very open to people using milk and sugar," Corby said. However, he explained that most people only add these to make up for having bad coffee in the first place.

"Sugar balances out bitterness which you get by over-roasting it, and milk helps to [hide] defects still showing up in the coffee," he said.

"Taking milk and sugar is not a bad thing, it covers up bad flavours coming in the coffee.

"However, if you buy coffee from a great roaster or someone roasting a bit lighter, if you taste it before you put milk and sugar in, you might find it doesn't need those two things."

8. Buying instant for a cheap, easy fix

Perhaps unsurprisingly, Corby recommends staying away from instant coffee — and he has a few good reasons.

"Instant coffee is very cheap," he said. "If you were to extrapolate out the cost of a bag of 250g of beans used to produce instant coffee, the price of the beans is extremely low."

However, he added that the process used to produce instant coffee is "extremely technical and costly" involving high-pressure brewing methods and freeze-drying.

"It's not a cheap product to make, but you find instant coffee cheap on the shelf," he said. "If you can buy coffee that cheap, there's a lot of things wrong with the supply chain — including what's being paid to the farmer and the quality of beans."

He added: "I can't even think of a bottle of wine still being sold that's as low-quality as instant coffee."

While he says the UK is one of the few markets in the world still consuming instant coffee, there's a shift in the way people are drinking.

"I do think that we're moving away from it as a nation," he said. "It's a positive move, [both] looking at how it impacts farmers and how it impacts consumers — it just brings a much better cup of coffee by buying beans or ground."

9. Not knowing how much caffeine you're consuming

If you're having a daily cup of joe, you may want to avoid going overboard — but most people view caffeine the wrong way.

"One really common misconception is that espresso has the highest extraction of caffeine you can drink, so people looking for a caffeine hit might run to a coffee shop and buy a double espresso," he said. "In actual fact, it just has a dense hit of caffeine.

"If you plan on drinking 200ml of liquid, and you think 'I'm going to drink a double espresso and a bottle of water,' or 200ml of filter coffee, you get more caffeine from the filter coffee because of the time it takes to brew."

He explained: "Caffeine goes into coffee in relation to the time coffee takes to brew rather than the pressure and density with which it brews."